The third Stanford-Livermore workshop in the series examining the protection of critical national infrastructures against cyber attack was held at Lawrence Livermore National Laboratory on February 26-27, 1998. The first two workshops were intended to provide informed inputs to the work of the President's Commission on Critical Infrastructure Protection, and the third, which came soon after the publication of the Commission's report to the President (entitled Critical Foundations), was directed toward a critical review of that report and to developing suggestions for steps to implement its findings in four areas that are considered particularly important: criteria and priorities to guide near-term actions; creation of a public-private partnership; legal issues, with some emphasis on understanding impediments to cooperation; and facilitation of research and development planning, with a subtheme on the robustness of complex systems.